If you find yourself consistently pushing out work to the next sprint, then I have some bad news for you.
You’re not doing anything closely related to either SCRUM or Agile, you’re simply doing work and let it roll on and on and on and never delivering anything.
If it takes you six weeks to deliver something you thought would take two, learn from it, what could you have done better? What made you think you could do it in two? How can you plan for it better next time and avoid the same mistakes?
If you can’t avoid the same mistakes and are content with continually rolling to the next sprint that is fine, but don’t kid yourself on what you’re doing.